1. Technical Field
The disclosure relates to field emission displays and, specifically, to a field emission cathode device and display using the device.
2. Discussion of Related Art
Field emission displays (FEDs) are a new, rapidly developing flat panel display technology. Compared to conventional technologies, such as cathode-ray tube (CRT) and liquid crystal display (LCD) technologies, FEDs are superior in providing a wider viewing angle, lower energy consumption, smaller size, and higher quality. In particular, carbon nanotube-based FEDs (CNTFEDs) have attracted much attention in recent years.
Generally, FEDs can be roughly classified into diode and triode structures. Diode structures have only one cathode electrode and only one anode electrode, and are only suitable for displaying characters, not for applications requiring high resolution. The diode structures require high voltage, produce relatively non-uniform electron emissions, and require relatively costly driving circuits. Triode structures were developed from diode structures by adding a gate electrode for controlling electron emission. Triode structures can emit electrons at relatively lower voltages.
Referring to FIGS. 4 and 5, a triode field emission cathode device 100, according to the prior art, is disclosed. The field emission cathode device 100 includes an insulating substrate 102, a number of longitudinal cathodes 104 attached on the substrate 102, a number of field emission units 110 distributed on the cathodes 104, a dielectric layer 106, and a number of gate electrodes 108 directly mounted on the top of the dielectric layer 106. The cathodes 104 are spaced and parallel. The field emission units 110 are arranged in series on the cathodes 104. The field emission units 110 are electrically connected to the cathodes 104 and have a number of field emitters mounted thereon. The dielectric layer 106 includes a number of through holes 116 exposing the cathodes 104 and the field emission units 110. An axis of the gate electrode 108 is perpendicular to that of the cathodes 104. Due to detachability between the gate electrodes 108 and the dielectric layer 106, the gate electrodes 108 are prone to sliding and deformation relative to the dielectric layer 106 during packaging of the field emission cathode device 100. In addition, during operation of the field emission cathode device 100, the gate electrodes 108 are easily distorted by the electric field, which results in a short circuit between the cathodes 104 and the gate electrodes 108. Therefore, the distance between the cathodes 104 and the gate electrodes 108 cannot be too short, and preferably exceed 20 microns (μm). However, as the distance between the cathodes 104 and the gate electrodes 108 increases, working voltage of the gate electrodes 108 must increase accordingly. The high working voltage affects the field emission performance of the field emission cathode device 100.
What is needed, therefore, is a field emission cathode device and a field emission display with lower working voltage and a higher field emission performance.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate at least one embodiment of the present field emission cathode device and field emission display using the same, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.